This is Richard Allen at the University of Iowa. This video demonstrates an external dacryocystorhinostomy or DCR.
A marking is made on the side of the nose half way between the bridge of the nose and the medial canthus. The marking extends approximately 1.5 cm from the level of the medial canthus toward the ala of the nose.
An incision is made along the marking.
Blunt dissection is performed with Stevens scissors to the underlying bone.
Four 4-0 silk sutures are then placed through the edges of the incision to provide exposure during the case.
The Freer periosteal elevator is then used to elevate the periosteum from the bone to the level of the anterior lacrimal crest.
The medial canthal tendon is disinserted to provide greater exposure.
The anterior lacrimal crest is identified and the lacrimal sac is elevated from the lacrimal sac fossa.
The thin bone of the posterior lacrimal fossa is broken with the Freer.
Rogeurs of increasing size are then used to remove bone of the lacrimal sac fossa.
This is performed anteriorly to the anterior lacrimal crest, superiorly to the level of the medial canthal tendon, posteriorly to the posterior lacrimal crest, and inferiorly to the beginning of the nasolacrimal duct.
The nasal mucosa is infiltrated with lidocaine with epinephrine.
A Bowman probe is then placed through the upper system where the medial lacrimal sac is palpated.
A number 66 Beaver blade is then used to make an incision through the lacrimal sac to develop the anterior lacrimal sac flap.
The Bowman probe is identified.
The Westcott scissors are then used to make the posterior flap.
The Beaver blade is then used to make a corresponding incision in the nasal mucosa.
The anterior flap in the nasal mucosa is then developed.
The posterior flap is then developed with the Westcott scissors.
The posterior flaps are then apposed and sutured to each other with a 4-0 chromic suture on a half circle needle. Two sutures are usually placed. Some surgeons like to place three.
The lacrimal sac mucosa is engaged followed by the nasal mucosa.
The Crawford stents are then placed through the system and retrieved from the nose with a Crawford hook.
The same is performed for the upper system.
I placed a 4-0 silk suture around the stents at the level of the ostium to prevent post-operative stent prolapse.
The anterior flaps are then sutured together with the same 4-0 chromic suture. Again two sutures are usually placed, sometimes three if needed. In this case the upper spot will be closed with a third suture.
The incision is then closed with deep interrupted 5-0 vicryl sutures.
The skin is then closed with interrupted 5-0 fast absorbing suture.
The patient returns at one week for evaluation. The stents are tied together and allowed to retract into the nose. I remove the stents at 4 months.
Inspection of the stent shows it to be in good position without tension.